Electroluminescent element with banks intersecting anode group

ABSTRACT

In order to provide a bright, color, simple matrix-type electroluminescent element which can be manufactured by means of a simple process, banks  4  required for fabricating organic films head in an electroluminescent element by means of an ink-jet are formed such that they intersect orthogonally with anodes  6,  and patterning of cathodes  1  is carried out using these banks. By means of this composition, cathode patterning becomes possible without increasing the number of processes. Therefore, it becomes possible to manufacture a full-color simple matrix-type electroluminescent element, inexpensively.

TECHNICAL FIELD

The present invention relates to a structure and a composition for anelectroluminescent element which can be used in a lap-top computer,television, mobile communications display, or the like, for example.

BACKGROUND ART

Electroluminescent elements which make use of the electroluminescence ofan organic compound have features such as high visibility due to theirself-luminescence, excellent shock resistance properties due to theircomplete solid state structure, and low drive voltage requirements,etc., and therefore they have received attention for use as luminescentelements in display devices of various types. In order to broaden theuse of the aforementioned organic EL (electroluminescent) elements, itis evident that multicolour display capacity is required, as seen incathode ray tubes (CRT), liquid crystal displays (LCD), and the like.

Conventionally known methods for fabricating a multicolour displaydevice using EL elements include, for example: (1) a method whereby ELmaterials which emit light in the three primary colours of red (R),green (G) and blue (B) are arranged in a matrix configuration (JapanesePatent Laid-open No. 1577487/1982, Japanese Patent Laid-open No.147989/1983, Japanese Patent Laid-open No. 214593/1991, and the like);(2) a method whereby the three primary colours, R, G, B, are extractedby combining colour filters with an EL element emitting white light(Japanese Patent Laid-open No. 315988/1989, Japanese Patent Laid-openNo. 273496/1990, Japanese Patent Laid-open No. 194895/1991, and thelike); (3) a method whereby an EL element emitting red light and afluorescence converting film are used to convert to the three primarycolours, R, G, B (Japanese Patent Laid-open No. 3-152897). However, themethods (2) and (3) described above both have a similar structure to thecolour filter used in a colour liquid crystal display device, andconsequently they require approximately the same level of expenditure.Moreover, in the method described in (1) above, three different types ofluminescence material must be arranged in a very fine matrixconfiguration.

Therefore, as disclosed in Japanese Patent Laid-open No. 227276/1996, inthe method in (1), the luminescent materials for the respective coloursare formed over a physical mask in order to fabricate the light-emittinglayers for the different colours. Moreover, in U.S. Pat. No. 5,294,869,high walls and low walls are provided between pixels, light-emittinglayers are fabricated separately for each colour according to the heightof the walls and the vapour deposition angle of electroluminescentmaterial, and furthermore, electrodes are formed by patterning using theaforementioned walls.

However, in methods using a physical mask, not only does the positionalregistration of the physical mask involve enormous work, but also it istechnologically difficult to fabricate a suitable physical mask whenmanufacturing panels of very high definition, and even supposing thatsuch a mask can be fabricated, it is difficult to carry out accuratepatterning of the light-emitting layers. Therefore, it is notpracticable to manufacture a high-definition colour panel using physicalmasks. Moreover, in methods which involve creating walls between pixels,it is necessary to build in the high walls and low walls, andfurthermore, a plurality of light-emitting layers must be formed by aplurality of vapour deposition operations whilst varying the vapourdeposition angle in the vacuum system.

The present invention overcomes these problems associated with the priorart. A first object of the present invention is to provide aninexpensive electroluminescent element having a novel compositionenabling colour display, by providing banks capable of separatinglight-emitting layers in a passive-drive electroluminescent element.

A second object of the present invention is to provide a manufacturemethod whereby an electroluminescent element having a novel compositionenabling colour display can be manufactured inexpensively, by comprisingsteps of forming banks in a passive-drive electroluminescent element andintroducing light-emitting material therebetween.

DISCLOSURE OF THE INVENTION

The invention achieving the first object is an electroluminescentelement provided with layers of electroluminescent material interposedbetween anodes and cathodes, characterized in that it comprises: ananode group formed by parallel arrangement of a plurality of anodes; abank group formed by parallel arrangement of banks intersecting with theanode group and having a height which prevents outflow of theelectroluminescent material introduced during manufacture;electroluminescent material layers formed inbetween the banks; and acathode group wherein cathodes running in the longitudinal direction ofthe electroluminescent material layers are provided on theelectroluminescent material layers and are separated electrically foreach of the electroluminescent material layers by means of the banks. Byadopting a structure which is partitioned by banks, theelectroluminescent material layers can be manufactured readily byintroducing a liquid of electroluminescent material, and cathodeformation can also be carried out in a single operation.

Here, the cathodes are formed in a continuous fashion over a side faceof the banks facing in a prescribed direction, the top face of thebanks, and the electroluminescent material layers. By adopting thisstructure, patterning of the cathodes is carried out simultaneously withvapour deposition of the cathodes by making use of the shadow of thebanks. Therefore, it is possible to carry out patterning of cathodesformed on organic films which are delicate with respect to processing.

Moreover, the angle formed between at least one side face of the banksand the face on which the banks are installed is an acute angle. Byadopting this structure, the cathodes can be formed separately bydepositing cathode material from a single direction, and the reliabilityof patterning can be improved. Moreover, a uniform distance can bemaintained between the banks. Thereby, it becomes easier to hit desiredpixels when a liquid of electroluminescent material is injected by meansof an ink-jet head, for example.

Furthermore, the angle formed between at least one side face of thebanks and top face thereof is an acute angle. By adopting thisstructure, since regions where no cathode material is deposited aregenerated by the shadow of the banks, the separation of the cathodes iscarried out automatically and reliably, and the reliability ofpatterning can be increased.

Furthermore, the electroluminescent material layers are constituted bylight-emitting layers and/or charge transporting layers. The chargetransporting layers may be hole injecting and transporting layers orelectron injecting and transporting layers. Here, the light-emittinglayers emitting light in each of the primary colours for the purpose ofproviding a colour display are arranged sequentially.

Moreover, in the present invention, each of the anodes constituting theanode group and each of the cathodes constituting the cathode group areconnected individually, means being provided for conducting simplematrix driving of the electroluminescent element. By means of thisstructure, it becomes possible to drive the electroluminescent elementby time division, thereby providing an inexpensive, high-capacity,colour electroluminescent element.

The invention for achieving the second object is a method formanufacturing an electroluminescent element provided with layers ofelectroluminescent material interposed between anodes and cathodes,characterized in that it comprises the steps of: forming an anode groupby parallel arrangement of a plurality of anodes on a substrate; forminga bank group by parallel arrangement of banks intersecting with theanode group and having a height which prevents outflow of theelectroluminescent material in an electroluminescent material formingstep; forming electroluminescent material layers by introducing a liquidof the electroluminescent material inbetween the banks; and forming acathode group wherein cathodes are electrically separated by means ofthe banks, by depositing cathode material onto the electroluminescentmaterial layers from a direction which forms a prescribed angle with thelongitudinal direction of the banks. By means of these steps, it ispossible to form the electroluminescent material layers at normalpressure whilst separating them by means of the banks, without requiringvacuum batch processing involving vapour deposition, or the like.

Moreover, the cathodes can be patterned very finely into thinrectangular shapes for the purpose of simple matrix driving. Here, thebanks may be formed such that the angle between the side faces thereofand the face on which the banks are installed is a right angle, thecathode group being formed by depositing cathode material by obliquevapour deposition from a direction confronting the side faces, or adirection perpendicular to the vertical direction of the banks. By thismeans, cathode patterning is completed simultaneously with cathodevapour deposition, making use of the shadow of the banks. Therefore, itis possible to carry out patterning of cathodes formed on organic filmswhich are delicate with respect to processing.

Moreover, the banks may be formed such that the angle between at leastone side face of the banks and the face on which the banks are installedis an acute angle, the cathode group being formed by depositing cathodematerial by oblique vapour deposition from a direction confronting theone side face or the vertical direction of the banks. Thereby, thereliability of cathode patterning can be increased and the distancebetween banks can be kept the same as cases where the banks have arectangular shape, and therefore it becomes easier to hit desired pixelswhen film material is injected by means of an ink-jet head, or the like.

Moreover, the banks may be formed such that the angle between at leastone side face of the banks and the top face thereof is an acute angle,the cathode group being formed by vapour deposition from the verticaldirection of the banks. By this means, it is possible to increase thereliability of cathode patterning. Furthermore, non-glare treatmentand/or antireflection treatment may be carried out on the surface of theelectroluminescent element. By this means, it is possible to improvecontrast in the electroluminescent element when used in brightlocations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an electroluminescent element in a firstembodiment of the present invention;

FIG. 2 is a sectional view along A—A of the electroluminescent elementin FIG. 1;

FIG. 3 is a sectional view along B—B of the electroluminescent elementin FIG. 1;

FIG. 4 is a sectional view of an electroluminescent element according toa first embodiment of the present invention, in a plane perpendicular tothe longitudinal direction of the banks (sectional view along C—C of theelectroluminescent element in FIG. 1).

FIG. 5 is a sectional view of an electroluminescent element according toa first embodiment of the present invention, in a plane perpendicular tothe longitudinal direction of the banks, illustrating a manufacturingprocess for same;

FIG. 6 is a sectional view of an electroluminescent element according toa second embodiment of the present invention, in a plane perpendicularto the longitudinal direction of the banks;

FIG. 7 is a sectional view of an electroluminescent element according toa second embodiment of the present invention, in a plane perpendicularto the longitudinal direction of the banks, illustrating a manufacturingprocess for same;

FIG. 8 is a sectional view of an electroluminescent element according toa third embodiment of the present invention, in a plane perpendicular tothe longitudinal direction of the banks;

FIG. 9 is a sectional view of an electroluminescent element according toa third embodiment of the present invention, in a plane perpendicular tothe longitudinal direction of the banks, illustrating a manufacturingprocess for same;

FIG. 10 is a simple connection diagram showing an electroluminescentelement and driving means according to a fifth embodiment of the presentinvention; and

FIG. 11 is a simple drive waveform diagram for an electroluminescentelement according to a fifth embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment)

The present embodiment is a passive-drive electroluminescent elementprovided with layers of electroluminescent material interposed betweenanodes and cathodes, characterized in that it comprises: an anode groupformed by parallel arrangement of a plurality of anodes; a bank groupformed by parallel arrangement of banks intersecting with the anodegroup and having a height which prevents outflow of theelectroluminescent material introduced during manufacture;electroluminescent material layers formed inbetween the banks; and acathode group wherein cathodes running in the longitudinal direction ofthe electroluminescent material layers are provided on each of theelectroluminescent material layers and are separated electrically bymeans of the banks. By means of the structure partitioned by banks, theelectroluminescent material layers can be manufactured readily byfilling in a liquid of electroluminescent material, and cathodeformation can also be carried out in a single operation.

FIG. 1 is a plan view illustrating the structure of anelectroluminescent element according to the first embodiment; FIG. 2 isa sectional view along A—A in FIG. 1; FIG. 3 is a sectional view alongB—B in FIG. 1; and FIG. 4 is a sectional view along C—C in FIG. 1. Asthese drawings show, the electroluminescent element according to thepresent embodiment comprises: an anode group formed by arranging aplurality of anodes 6 in parallel on a transparent substrate 7; a bankgroup formed by arranging in parallel a plurality of banks 4intersecting with the anode group and having a height which preventsoutflow of electroluminescent material introduced during manufacture; ahole injecting and transporting layer 5 and light-emitting layers 2constituted by electroluminescent material layers formed between thebanks 4; a cathode group wherein cathodes 1 running in the longitudinaldirection of the electroluminescent material layers are provided on eachof the electroluminescent material layers and are separated electricallyby means of the banks 4; and a protective layer 3. A characteristicfeature of the cathodes 1 is that, according to their fabricationmethod, they are formed in a continuous fashion on one side face of thebanks 4 facing in a uniform direction, the top face of the banks, andthe electroluminescent material layers. The longitudinal direction ofthe anodes 6 should intersect with, but not necessarily in aperpendicular fashion, the longitudinal direction of the banks 4, holeinjecting and transporting layers 5, light-emitting layers 2, cathodes1, and the like. The electroluminescent material layers may comprise ahole injecting and transporting layer for raising the transportationfunction of holes, a light-emitting layer for generating fluorescentlight by application of an electric field, and an electron injecting andtransporting layer for raising the transportation function of electronholes.

Next, a method for manufacturing an electroluminescent element havingthe aforementioned structure is described. Firstly, Indium Tin Oxide(ITO) was deposited onto a clean glass substrate (transparent substrate7) by EB vapour deposition to form a transparent electrode, whereuponelectrodes 6 were fabricated by patterning this electrode in thinrectangular shapes. Moreover, as shown in FIG. 4, a photosensitiveresist and a contrast enhancing layer were applied and pattern exposurewas carried out to fabricate longitudinal banks 4. In this process, thebanks were formed to a height exceeding the total thickness of theelectroluminescent material layers formed subsequently, as illustratedin FIG. 4. This height is adjusted such that a liquid ofelectroluminescent material will not spill over the banks when it isintroduced. In this case, the height of the banks was set to 2 μm. Asshown in FIG. 5, the banks 4 were formed such that the longitudinaldirection thereof intersected with the longitudinal direction of theaforementioned anodes 6. Thereupon, using an ink-jet head, a holeinjection material in the form of a 1:1 mixture of copper phthalocyanineand epoxypropyl triethoxysilane in an ethoxyethanol dispersed solutionwas injected inbetween the banks, and calcinated for 5 minutes at 200°C. to form hole injecting and transporting layers 5 of 10 nm filmthickness. In the group of green-coloured pixels, an aqueous solution ofa water-soluble precursor of PPV-G (chemical formula 1) was appliedthereto by means of an ink-jet head and then calcinated for 4 hours at150° C. to form green light-emitting layers 2 g of 100 nm filmthickness. In the group of blue-coloured pixels, an aqueous solution ofa water-soluble precursor of PPV-B (chemical formula 2) was applied bymeans of an ink-jet head and then calcinated for 4 hours at 150° C. toform blue light-emitting layers 2 b of 100 nm film thickness. In thegroup of red-coloured pixels, an aqueous solution of a water-solubleprecursor of PPV-R (chemical formula 3) was applied by means of anink-jet head and then calcinated for 4 hours at 150° C. to form redlight-emitting layers 2 r of 100 nm film thickness.

As shown in FIG. 5, the cathodes 1 were fabricated by EB vapourdeposition of an alloy of Mg:Ag (10:1) forming the cathode material in adirection inclined by 45° with respect to the face on which the banksare installed, in other words, the normal to the panel. Since thecathodes were vapour deposited from a direction confronting the sidefaces of the banks, regions affected by the banks were generated, andconsequently, the cathodes were electrically separated for each pixelwithout needing to carry out a special patterning operation. Moreover, aprotective layer 3 was formed by moulding an epoxy resin. As theprotective layer, besides epoxy resin, it is possible to use athermosetting resin, ultraviolet-setting resin, silicon resin containingpolysilazane, or the like, provided that the resin is capable ofshutting out air and moisture, and it does not interfere with theorganic film. Furthermore, the cathodes 1 may be subjected topatterning, if vapour deposition is carried out in the direction of thenormal to the panel.

Here, copper phthalocyanine was used as the hole injecting materialforming the electroluminescent material in the hole injecting andtransporting layer 5, but materials such as porfine compounds, TPD(chemical formula 4), m-MTDATA (chemical formula 5), NPD (chemicalformula 6), polyvinyl carbazole, TAD (chemical formula 7), polyaniline,carbon, or the like, may be used similarly, provided that they have ahole injecting function. Combinations or laminated structures of thesecompounds may also be used.

For the light-emitting layers 2, in addition to the foregoingdescription, it is also possible to use PPV or derivatives thereof,complexes based on metal quinolinol derivatives or azomethinederivatives, DPVBi (chemical formula 8), tetraphenyl butadiene,oxadiazol derivatives, polyvinyl carbazole derivatives, or the like, andfurthermore, it is also possible to add to these compounds, materials,such as perylene, cumarine derivatives, DCM1 (chemical formula 9),quinacridone, rubrene, DCJT (chemical formula 10), Nile red, or thelike. Moreover, fluorescence converting materials may be combined orlaminated. (Chemical formula 8) DPVBi

(Second Embodiment)

In this embodiment, an example is illustrated wherein the banks areformed such that the angle formed between at least one side face thereofand the face on which the banks are installed is an acute angle.

FIG. 6 gives a sectional view of an electroluminescent element accordingto the present embodiment along a plane perpendicular to thelongitudinal direction of the banks. The electroluminescent elementaccording to the present embodiment comprises: a transparent substrate7, anodes 6, hole injecting and transporting layers 5, banks 4, aprotective layer 3, light-emitting layers 2, and cathodes 1. With theexception of the shape of the banks, this embodiment is the same as thefirst embodiment described above, and therefore description thereof isomitted. The present embodiment is characterized in that the banks 4 arefabricated such that the angle formed between one side face thereof andthe face on which the banks are installed is an acute angle.

Next, a method for manufacturing an electroluminescent element accordingto this embodiment is described. The processing steps prior to formationof the banks are similar to the first embodiment. In the bankfabrication process, firstly, a resist layer consisting of bank materialwas formed to a thickness of 2 μm, and was then exposed to light througha photo mask at an angle of 45° with respect to the normal to the panel.Thereupon, etching was performed to fabricate banks 4 having aparallelogram-shaped cross-section. The subsequent ink-jet process wassimilar to that in the first embodiment. After forming thelight-emitting layers 2, cathodes 1 were fabricated by EB vapourdeposition of an Mg:Ag (10:1) alloy as the cathode material from thedirection of the normal to the panel. The processing from this stageonwards was similar to that in the first embodiment.

According to this embodiment, since a side face of each bank forms anobtuse angle with the installation face of the banks, it is possible toform separated cathodes by depositing a cathode material from a singledirection, and it is possible to increase the reliability of patterning.Moreover, it is possible to maintain a uniform distance between banks.When injecting electroluminescent material by means of an ink-jet head,for example, it becomes easier to hit the desired pixel.

(Third Embodiment)

In this embodiment, an example is illustrated wherein thecross-sectional shape of the aforementioned bank is an inverted platformshape, and the aforementioned cathode material is vapour deposited froma perpendicular direction with respect to the side face of the panel.

FIG. 8 is a sectional view of an electroluminescent element according tothe present embodiment, cut in a plane which is perpendicular to thelongitudinal direction of the banks. The electroluminescent elementaccording to the present embodiment comprises: a transparent substrate7, anodes 6, hole injecting and transporting layers 5, banks 4, aprotective layer 3, light-emitting layers 2 and cathodes 1. With theexception of the shape of the banks 4, this embodiment is similar to thefirst embodiment, and description thereof is omitted here. The presentembodiment is characterized by the fact that the banks 4 are fabricatedsuch that the angle formed between at least one side face of the banks 4and the top face thereof is an acute angle.

Next, a method for manufacturing the electroluminescent elementaccording to the present embodiment is described. The processing stepsprior to formation of the banks are similar to the first embodiment. Inthe bank fabrication process, firstly, a resist layer consisting of bankmaterial was formed to a thickness of 2 μm, and furthermore, a contrastenhancing layer was formed. Light exposure was then carried out througha photo mask at an angle of 45° with respect to the normal to the panel.Thereupon, over-etching was performed to fabricate banks 4 having aninverted platform-shaped cross-section. Subsequent ink-jet processingwas similar to that in the first embodiment. After forming thelight-emitting layers 2, cathodes 1 were fabricated by EB vapourdeposition of an Mg:Ag (10:1) alloy as the cathode material from thedirection of the normal to the panel. The processing from this stageonwards was similar to that in the first embodiment.

According to this embodiment, since regions where no cathode material isdeposited are formed under the shelter of the banks, separation of thecathodes is achieved automatically, and the reliability of patterningcan be increased.

(Fourth Embodiment)

This embodiment illustrates an example where non-glare treatment and/orantireflection treatment is carried out on the surface of theelectroluminescent element. When an AG-20 non-glare film manufactured byHitachi Denko Co. Ltd. was applied to the front surface of the panel,reflection of ambient light was reduced and contrast was improved.Furthermore, when antireflection treatment was applied to the surface ofthe AG-20 film, there was virtually no reflection of ambient light andcontrast was improved remarkably.

The non-glare film to be used is not limited to the types shown here,and any type of non-glare film having a similar effect may be used.Moreover, in this case, “Saitop” manufactured by Asahi Glass Co. Ltd.was used for the antireflection treatment, but besides this, it is alsopossible to use a multilayer coating or low-diffraction-index materialcoating, or the like.

(Fifth Embodiment)

This embodiment illustrates an example wherein a large-capacity displayis carried out by connecting simple matrix driving means to theaforementioned electroluminescent element. FIG. 10 shows the compositionof this electroluminescent element. As shown in FIG. 10, this displaysystem comprises: the aforementioned electroluminescent element 12, ascanning electrode driver 13, a signal electrode driver 14 and acontroller 15. The outputs of the signal electrode driver 14 areconnected to the respective anodes 4 constituting the anode group, andthe outputs of the scanning electrode driver 13 are each connectedindividually to the respective cathodes 1 constituting the cathodegroup. The controller 15 represents means for simple matrix driving ofthe electroluminescent element 12, and it is constituted such that ascanning electrode signal driven by time division can be supplied to thescanning electrode driver 13 and a signal electrode signal can besupplied to the signal electrode driver 14. The electroluminescentelement 12 comprises an anode group of 100 anodes and a cathode group of320 cathodes, and it is connected as illustrated in FIG. 10. An exampleof drive waveforms applied to the anodes and cathodes is shown in FIG.11. In this diagram, Tf indicates scanning time. Here, the system isdriven at 1/100 duty. In this drive system, a waveform of sufficientvoltage Vs to cause light emission and a pulse width which matches thetonal gradation to be displayed is applied to selected pixels. A voltageVn below the light emission threshold voltage is applied to pixels whichare not selected.

When an image display was carried out using a display system based on anelectroluminescent element fabricated according to any one of the firstembodiment to the fourth embodiment, it was possible to achieve a clearand vivid colour display.

According to the present embodiment, the electroluminescent element canbe driven by time division, thereby enabling an inexpensivehigh-capacity colour electroluminescent element to be achieved.

INDUSTRIAL APPLICABILITY

According to the present invention, it is possible to provide afull-colour electroluminescent element capable of being driven by simplematrix drive, inexpensively, by means of a simple process. Therefore,the electroluminescent element can be used in colour displays forinexpensive portable terminals, car-mounted displays, and the like.

What is claimed is:
 1. An electroluminescent element provided withlayers of electroluminescent material interposed between anodes andcathodes, the electroluminescent element comprising: an anode groupformed by parallel arrangement of a plurality of anodes; a bank groupformed by parallel arrangement of banks intersecting with said anodegroup and having a height which prevents outflow of saidelectroluminescent material introduced during manufacture; saidelectroluminescent material layers formed between said banks; and acathode group, wherein cathodes running in the longitudinal direction ofsaid electroluminescent material layers are provided on saidelectroluminescent material layers and are separated electrically foreach of said electroluminescent material layers by means of said banks,and wherein said cathodes are formed in a continuous fashion over a sideface of said banks facing in a prescribed direction, over the top faceof said banks in direct contact with said top face, and over saidelectroluminescent material layers.
 2. The electroluminescent elementaccording to claim 1, characterized in that each of the anodesconstituting said anode group and each of the cathodes constituting saidcathode group are connected individually, further comprising means forproviding simple matrix driving of said electroluminescent element. 3.The electroluminescent element according to claim 1, characterized inthat the angle formed between at least one side face of said banks andthe face on which said banks are installed is an acute angle.
 4. Theelectroluminescent element according to claim 1, characterized in thatthe angle formed between at least one side face of said banks and topface thereof is an acute angle.
 5. The electroluminescent elementaccording to claim 1, wherein said electroluminescent material layerscomprise light-emitting layers and charge transporting layers.
 6. Theelectroluminescent element according to claim 1, wherein saidelectroluminescent material layers comprise light-emitting layers. 7.The electroluminescent element according to claim 6, characterized inthat said light-emitting layers emitting light in each of the primarycolours for the purpose of providing a colour display are arrangedsequentially.
 8. A method for manufacturing an electroluminescentelement provided with layers of electroluminescent material interposedbetween anodes and cathodes, the method comprising: forming an anodegroup by parallel arrangement of a plurality of anodes on a substrate;forming a bank group by parallel arrangement of banks intersecting withsaid anode group and having a height which prevents outflow of saidelectroluminescent material in an electroluminescent material formingstep; forming electroluminescent material layers by introducing a liquidof said electroluminescent material between said banks; and forming acathode group wherein cathodes are electrically separated by means ofsaid banks, by depositing cathode material onto said electroluminescentmaterial layers from a direction which forms a prescribed angle with thelongitudinal direction of said banks, wherein forming the cathode groupincludes forming the cathodes continuously over a side face of saidbanks facing in a prescribed direction, over the top face of said banksin direct contact with said top face, and over said electroluminescentmaterial layers.
 9. The method for manufacturing an electroluminescentelement according to claim 8, characterized in that said banks areformed such that the angle between the side faces thereof and the faceon which said banks are installed is a right angle, and said cathodegroup is formed by depositing cathode material by oblique vapourdeposition from a direction confronting said side faces, or a directionperpendicular to the vertical direction of said banks.
 10. The methodfor manufacturing an electroluminescent element according to claim 8,characterized in that said banks are formed such that the angle betweenat least one side face of said banks and the face on which said banksare installed is an acute angle, and said cathode group is formed bydepositing cathode material by oblique vapour deposition from adirection confronting said one side face or the vertical direction ofsaid banks.
 11. The method for manufacturing an electroluminescentelement according to claim 8, characterized in that said banks areformed such that the angle between at least one side face of said banksand the top face thereof is an acute angle, and said cathode group isformed by vapour deposition from the vertical direction of said banks.12. The method for manufacturing an electroluminescent element accordingto claim 8, characterized in that non-glare treatment is carried out onthe surface of said electroluminescent element.
 13. The method formanufacturing an electroluminescent element according to claim 8,characterized in that the formation of said electroluminescent materiallayer is carried out by injecting and filling a liquid ofelectroluminescent material inbetween said banks by means of an ink-jetmethod.
 14. The method for manufacturing an electroluminescent elementaccording to claim 8, characterized in that non-glare treatment andantireflection treatment are carried out on the surface of saidelectroluminescent element.
 15. A method for manufacturing anelectroluminescent element provided with layers of electroluminescentmaterial interposed between anodes and cathodes, the method comprising:forming an anode group by parallel arrangement of a plurality on asubstrate; forming a bank group by parallel arrangement of banksintersecting with said anode group and having a height which preventsoutflow of said electroluminescent material in an electroluminescentmaterial forming step; forming electroluminescent material layers byusing an ink jet to introduce a liquid of said electroluminescentmaterial between said banks; and forming a cathode group whereincathodes are electrically separated by means of said banks, bydepositing cathode material onto said electroluminescent material layersfrom a direction which forms a prescribed angle with the longitudinaldirection of said banks, wherein forming the cathode group includesforming the cathodes continuously over a side face of said banks facingin a prescribed direction, over the top face of said banks in directcontact with said top face, and over said electroluminescent materiallayers.